Concealable underarm holsters have been available to law enforcement officers for many years. Typically they have employed a single shoulder strap carrying a holster under one arm. A horizontal strap extending around the wearer's back, around his opposite shoulder and return across his back. This type of holster has reasonably held the holster in place, primarily due to the tension on the horizontal strap. It offers a major disadvantage, however, by exterting a constant backward pressure on the officer's shoulders and on his underarm which is uncomfortable but has become accepted.
A recent development has been the vest-type holster which is in fact patterned after a man's vest fully open in front and distributing the weight of the handgun across the top of the shoulders with minimum transverse pressure. A holster is secured under the arm and certain of these holsters carry an ammunition pouch or clip holder under the opposite arm to balance the weight. These vestlike harnesses sometime use shoulder straps of the type used in the above described older underarm holsters and an adjustable strap across the back. Typical is the vestlike carrier disclosed in U.S. Design Pat. No. D234,840.
It has been found that such harnesses do not prevent the holster and handgun from moving and in fact swinging, pendulum fashion when an officer runs. Such action is undesirable, giving the officer concern for the security of his handgun and distracting him. Drawing a swinging handgun is not an easy accomplishment.